Fluid-pressure-brake device



March 27, 1'92 8 T. H. THOMAS ET AL FLUID PRESSURE BRAKE DEVICE Filed May 14, 1926 QR m INVENTORS THOMAS I I HOM AS BY EARLES.COOK

ATTORNEY Patented Mar. 27,1928.

' e in brake pipe pressure and consequent THOMAS H. months, or EDsEwooD sYLv'ANIe, assieNoRs 'ro MERDING, PENNSYLVANIA, A coRroaArioN or PENNSYLVANIA.

* FLUIn-PR ssURE-BRAKE evice. Y

Application med .iita 14,

1 Lor' split reduction method of handling the Y brakes, especially on long trains, as employed by' engineers, in "which the engineer first 7 makesa lightreduc-tion inbrake pipe pressure to effect a; light application otthe brakes sufficientfto causethe. brakes tobe lightlyapplied and thenafter a'time, sufli cient to permit'therslack to be bunched, the engineer makes alieavier reduction in brake j pipe pressure to produce the desired application ofthe brakes. 1

I The time elapsing before the second reduction in brake pipe pressure is made should be varied to correspond withthe time re.-

quired for the slack to run in and this in turn depends upon the length of the train.

7 One object of our inventionis to provide means for automatically reflecting successive reductions in brake pipe pressure in-which thetime between the end of the first reduc- -tion and the beginning of the second reductionis varied according to the time required for effecting-the first reduction inbrake pipe pressure, so that the longer the train and the longer: the time required to efiect the first reduction, the longer the time which elapses before the second-reduction is started. Another object of our invention'is to processive reductions in brake pipe pressure, in which failure of the equalizing discharge valve to seat properly will not interfere with obtaining the desired reduction in brake pipe pressure and'in which such reduction will either be in the form of successive reductions ora corresponding continuous reduction; In the accompanying drawing, the single figure is a sectional diagrammatic view of an automatictrain control equipment embody} ing our invention. I i i I As shown in the drawing, the equipment 7 may comprise abrake valve device 1, having 50 an equalizing discharge rvalvedevice and having; associated" therewith an application valve device 2;a.-valve'device 3 for control 'lingsiiccessive reductions in brake pipe-pres vide means for automatically effecting suc- 1926. Serial No. ibs,o44.-

sure; a magnet controlled valve; device-4';

and an' acknowledging valve-devices,

The brake valve device 1 comprises acas-.

ing having valve chamber 6 containing arotary slide valve 7 adapted to beopera-ted by a" handle 8 and said casing contains the equalizing discharge valve device comprising "a piston "9 and a brake pipe discharge valve lO adapted to be operated by said-piston e e 1 i The chamber 1-1 at one side of piston is connected to the usual 1 "equalizing; reservoir nectedto the usual b'rake pipe'l4.- I

ANDIEARLE s. 06 K;orwn esmnefrenm Amenities coMP N or 11..-

, a '12 and'chamb'er '13 at the opposite sideis con v f,

K The application'valve device-2 comprises apiston 32 contained-,inpiston' chamber 15' and a'slide valve 16 containedin valve chain ber 17.' The split reduction 'cont rolling valve device 3 'comprises a casing having di tferential piston chambers 18 and 19mm taining pistons 20 'and"21"respective1y, said pistons being connected by a] stem 22 and being adapted to operate a. slide valve 23 contained in the intermediate valve1cham ber 24:.

The control valve casing is also provided Wlth a piston chamber 25 containing a piston 26 and a valve chamber- 27 containing aslide valve 28' adapted to be operatedbypiston26.-- v V The magnetcontrolle'd valve device4 comprises a magnet 29 and double beat valves 30 and 31 adapted to be controlled by said 'ma'gnet. The magnet iscontrolled according to to close the valve 30, so that'pipe-33ywhi'c h to the atmosphere. Fluid under pressure is the trufiic conditionsgand when',favoi'abl.e,

99 he magnet '29 "operates;

.is connected 'to piston chamberf15,;is'closed I I V I supplied from the main-reservoir 34throug-1i pip 35 and passages 36 and "37 to valve chamber release position, as'shown in-the'draw'ing.

The discharge passage 40 of the-discharge valvelO is open to the atmosphere through restricted port &1 and sets passage is 17 and. thence flows throughfthe restricted port 38 in piston '32 to piston". I I

side's ofpiston' 32 being thus balanced, the

' valve is held closed.

slide valve 16 and exhaust port 50. The

brake pipe 14 is connected through passage ,51 withpiston chamber 19 and the valve chamber 24 and piston chamber 18 being at atmospheric pressure, the brake pipepressure n piston chamber 19 holds the piston 21 in ts upper posit on, as shownv 1n the drawing The lock-up reservoir 52 being connectedtopassage 44, is also maintained, at atmospheric pressure.

y In the normal position of slide pistonchamber25 is: connected to theatmospherethrough passage 53, cavity in slide valve 23, passage 55,. and restricted exhaus port 56, so that spring 5Tholds slide valve .28and piston 26 in the position shown, the

valve. chamber 27 bein constaiitly open to theatmosphere through port58.

. The first reduction reservoir 59 con,- nected to thes'econd reduction reservoir 60 through pipe 61, passage 62, cavity Q63 in slide valve 28,. passage 64 andpipe 65.,

: The timing reservoir 66 is open to the l -atmosphere by way of passage 67, restricted a passage 70.

POrt 68, and past check valve 69 to passage- 53and passage 67 p is also open to valve chamber 27 and'thus to the atmosphere, in the normal position of slide valve 28, asv shownin the drawing.

When the magnet 29 becomes .deenergized due to the action of. the train controlfapparatus, th'e valve 30 is unseated. and li'uid under pressure is vented from piston [chamber 15 ,of the application valve device 2,

through pipe 33 and atmospheric exhaust Piston 32 is then shifted by the fluid pressure invalve chamber 17 and slide valve 16 is moved to a position in which the equalizing reservoir 12 and chamber 11 of the equalizing discharge valve device are connected to the firstreductio'n reservoir 59 through passage 71,,cavity72in slide valve '16, passage 73 and pipe'61. The pressure in the equalizing reservoir 12 isthus reduced by equalization into the first reduction reservoir '59, according to the relative volumes of said reservoirs, preferably such that the reduction in pressure will be about seven pounds. l

Piston 9 is then operated by the brake pipe :pressuriein chamber 13, 'so as to open the discharge valve 10' and permit fluid to be vented from the brake pipe 14 to the discharge passage 40. lVhen the brake pipe pressure has been reduced to a degree slightly valve 23, Y

less than the reduced pressure in the equalizing reservoir 12, the piston 7 operates to close the discharge valve 10.

.Fluid vented to the discharge passage40 flows .to the atmosphere through the restricted port 41 a-t a predetermined" rate which is less than the rate at which fluid is discharged from the brake'pipe to the passage 40. Consequently, the fluid pressure builds up in pipe 42 and in piston chamber 18 of the control valve device 3. When the fluid pressure in piston'ehamber 18 has been increased to a predetermined degree, dependent upon the reduction in brake pipe pressure in piston chamber 19, and therelative areas of, the pistons 20. and 21, for

example, to thirty pounds,- the piston 20 is shifted and slide valve 23-. is moved to a position incwhich passage 53 is conl'iecte d, through cavity 54 in slide valve 23 with passage 74. Passagev 74. is supplied with fluid at a pressure less than main-reservoir pressure as supplied by a pressure reducing valve device 75, andcconsequently the piston 26 is shifted byfllluid at reducing valvepressure supplied to piston chamber 25, so' that slide valve 28 is moved to cutoff communication between passages, 62 and .64. Consequently during the first reduction in brake pipe pressure, only the first reduction reservoir 59 is connected to the equalizing reservoir '12.

Fluid at reducing valve pressure also flows from passage 53, through the. restricted port 68- and passage 67 to the timing reservoir 66, charging sald reservoir at a predetermined rate, so long as piston 20 holds slide valve 23 iniits lower position. The lock-up reservoir 52 is charged with fluid at brake pipe pressure through passage 76, cavity 49 in application slide valve 16 passage. 48, pipe 47, passage 7.7, cavity 78 inslide valve 23, and passage 44. The movement. of slide valve 23 to itslower position also connects valve chamber 24 to the atmosphere, through port 43 and exhaust port 79, soas to prevent possibility of fluid leaking into said valve chamber and building up pressure therein which might interfere with the functioning of the first, reduction action.

As the discharge valve 10 moves toward its seat, the rate of flow of fluid from the brake pipe to the discharge passage 40 reduces and when less than the rate of dis-.

valve d'evi'c'e'subject to thepressureof fluid in said reservoir and operated upon a predetermined reduction in pressure in saidre'servoir for eflectin'g a second reduction in brake pipe pressure.

' 6;Ina fluid pressure brake, the combina- "tion with a brake pipe, of means for efi'ecting areduction in brake pipe pressure, a timing reservoir, a source of fluid under pressure, a valve device operated by fluid Vented from the brake pipe for supplying fluid from said source to said reservoir, a

tionlreservoir, a discliarge valve device operated upon reduction in fluid pressure for venting fluid from-thebrake pipe, means for connecting said discharge valve device tothe first reduction reservoir,a cut-ofl valve devicesubject to the pressure in said timing reservoir for controlling communication from the first to'the second reduction reservoir, and a. valve device having one position for supplying fluid underpressure to said timing reservoir, and another position in which fluid is vented from said reservoir.

8. In a fluid pressure brake, the combination with a brake pipe, of means for effecting successive reductions in brake pipe pressure including a first reduction reservoir, a second reduction reservoir, and a valve device for connecting the first to the second reduction reseri' oir, and a valve device for controlling the first mentioned valve device and subject to the opposing pressures of the brake pipe and fluid'vented from the brake pipe in effecting'a reduction in brake pipe pressure. I 9. Ina fluid pressure brake, the combination w"ith a brake pipe, of means for effecting'successi-v'e reductionsin brake pipe pressure including a controlling valve device subject to the opposing pressures of the brake pipe, and fluid vented from the brake pipe in effecting a reduction in brake pipe pressure. V

10. In a fluid pressure bra-kc, the combination with a brake pipe, of means for effect set our hands.

ing successive reductions in brake pipe pressure includ ng a controlling" valve device comprising connected pistons hav1ngdifierential areas, one piston; being subject to brake pipe pressure and the other to the pressure of fluid vented from the brake pipe in eflecting a reduction inbrake pipe pressure.

ential areas, one piston being su'bject' 'to brake pipe pressure and the other to the pressure of fluid vented from the brake pipe in effecting a reduction in brake -pipe pressure, a reservoir adapted tobe charged with fluid under pressure in one position of said the chamber intermediate said pistons-in antion t a brake p pe, of means for effect-- 11. In a fluid pressure brake, the combina- I valve device and adapted to be connected-t0 ing successive reductionsin brake pipejpr'essure including a timingreservoir, source 7 of fluid under pressure,- *and'avalve-device having one positionfon supplying fluid under pressure fI'OHl SElld' source t6 said reservoir at a predetermined restricted rate V and another position in which from said reservoir.

' 13. In a fluid pressure bralie,the combination with a brake pipe, of mea-ns for fluid vented eflecting successive reductions in Make pipe pressure including a timing reservoir,-iineaiis controlled by the fluid pressure in said res'er- 'voir for initiating a second reduction in brake pipe pressure, and means for-charg ing said reservoir at a predetermined restricted rate while the first reduction in brake pipe pressure is being effected.

14. In a fluid pressure brake, the combination with a brake pipe, of means for 'eifecting successive reductions in brake pipe pressure including a timing reservoir, a sourceof fluid under pressure, and a valve device having one position for supplying fluid under pressure from said source to said reservoir at a predetermined J restricted rate and another po'sition in which fluidis vented from said reservoir at a predeter mined restricted rate.

In testimony whereof we have hereunto Y THOMAS H. THOMAS, EARLE s. COOK. 

